黄原胶/CMC复合稳定剂对酪蛋白乳液稳定性的影响

研究了黄原胶/羧甲基纤维素钠复配比例及体系pH值对酪蛋白乳液ζ-电位、粒径、黏度、乳析稳定性及微观结构的影响,揭示了多糖稳定乳液或促进乳液失稳的机理。研究发现:中性条件下,两种阴离子多糖均未吸附到酪蛋白稳定的油滴表面,未吸附的多糖分子诱发了液滴的排斥絮凝,在宏观上表现为乳液的快速分层;酸性条件下,带负电荷的黄原胶或羧甲基纤维素钠分子吸附于酪蛋白包裹的油滴表面,提高了液滴间的静电斥力及空间位阻,在一定的复配比例下(羧甲基纤维素钠∶黄原胶=1∶1,3∶1,总添加量为乳液质量的0.4%),乳液的稳定性提高,在室温下存放两周,分层现象不明显。

Influence of xanthan and CMC mixture on the stability of sodium caseinate emulsions

The influences of the ratio of xanthan gum(XG) to sodium carboxymethyl cellulose(CMC) mixture and the pH on the behavior of oil-in-water caseinate emulsion were investigated.Zeta-potential,droplet size,viscosity,creaming behavior and the microstructure of the emulsion were detected to reveal the possible mechanisms of the stability or instability of the emulsion.Results show that,under neutral condition,both anionic polysaccharides were not absorbed to the surface of the caseinate-coated droplet,which caused the depletion flocculation.The creaming behavior of visual separation was quickly observed during the storage time.Under acid condition,xanthan gum or sodium carboxymethyl cellulose was absorbed to the droplet surface and increased both the electrostatic and steric repulsion of the emulsion.At certain polysaccharide concentrations(CMC∶XG = 1∶1,3∶1,the total addition amount of the emulsion is 0.4 wt%),the stability of the emulsion was enhanced,and during two weeks room temperature storage there was no notable creaming phenomenon.